System and method for preheating a beater mill

Patent metadata

Field	Value
Publication number	US-10976050-B2
Application number	US-202016849475-A
Country	US
Kind code	B2
Filing date	Apr 15, 2020
Priority date	Dec 2, 2016
Publication date	Apr 13, 2021
Grant date	Apr 13, 2021

Abstract

A method for preheating a beater mill is provided. The method includes: rotating a beater wheel disposed within the beater mill to facilitate circulation of a gas stream between the beater mill and a furnace fluidly connected to each other via both a pulverized fuel conduit and a flue gas recirculation conduit; generating a burner gas via a burner disposed within the flue gas recirculation conduit such that the burner gas joins and heats the gas stream circulating through the beater mill and the furnace; and adjusting at least one of an air supply and a fuel supply to the burner via a controller based at least in part on one of a temperature of the gas stream at an entrance of the beater mill, a temperature of the gas stream at an exit of the beater mill, and an oxygen level within the beater mill.

First claim

What is claimed is:

1. A method for preheating a beater mill comprising:
rotating a beater wheel disposed within the beater mill to facilitate circulation of a gas stream between the beater mill and a furnace fluidly connected to each other via both a pulverized fuel conduit and a flue gas recirculation conduit;
generating a burner gas via a burner disposed within the flue gas recirculation conduit such that the burner gas joins and heats the gas stream circulating through the beater mill and the furnace, wherein the gas stream circulating through the beater mill and the furnace is powered by the beater wheel; and
adjusting at least one of an air supply and a fuel supply to the burner via a controller based at least in part on one of a temperature of the gas stream at an entrance of the beater mill, a temperature of the gas stream at an exit of the beater mill, and an oxygen level within the beater mill.

2. The method of claim 1 , wherein the controller adjusts at least one of the air supply and the fuel supply of the burner such that the burner generates the burner gas at stoichiometric conditions.

3. The method of claim 1 , wherein adjusting at least one of an air supply and a fuel supply to the burner via a controller comprises:
adjusting at least one of the air supply and the fuel supply such that at least one of the temperature of the gas stream at the entrance of the beater mill is within a target mill entrance gas temperature range, and the temperature of the gas stream at the exit of the beater mill is within a target mill exit gas temperature range.

4. The method of claim 3 , wherein adjusting at least one of an air supply and a fuel supply to the burner via a controller further comprises:
adjusting at least one of the air supply and the fuel supply such that the oxygen level within the beater mill is below a maximum mill oxygen threshold.

5. The method of claim 4 further comprising:
obtaining the oxygen level within the beater mill from an oxygen sensor disposed in the beater mill or in the pulverized fuel conduit downstream of the beater mill.

6. The method of claim 4 further comprising:
calculating the oxygen level within the beater mill via the controller based at least in part on an oxygen level within the furnace obtained by an oxygen sensor disposed in the furnace or in an outlet of the furnace.

7. The method of claim 4 further comprising:
introducing a fuel into the beater mill from a fuel source when the oxygen level within the beater mill is below the maximum mill oxygen threshold.

8. The method of claim 7 further comprising:
introducing the fuel into the beater mill from a fuel source when at least one of:
the temperature of the gas stream at the entrance of the beater mill is within the target mill entrance gas temperature range; and
the temperature of the gas stream at the exit of the beater mill is within the target mill exit gas temperature range.

9. The method of claim 7 , wherein the fuel is coal.

10. A method for preheating a beater mill comprising:
rotating a beater wheel disposed within the beater mill to facilitate circulation of a gas stream between the beater mill and a furnace fluidly connected to each other via both a pulverized fuel conduit and a flue gas recirculation conduit;
generating a burner gas via a burner disposed within the flue gas recirculation conduit such that the burner gas joins and heats the gas stream circulating through the beater mill and the furnace;
adjusting at least one of an air supply and a fuel supply to the burner via a controller such that the burner generates the burner gas at stoichiometric conditions and based at least in part on one of a temperature of the gas stream at an entrance of the beater mill, a temperature of the gas stream at an exit of the beater mill, and an oxygen level within the beater mill.

11. The method of claim 10 , further including:
adjusting at least one of the air supply and the fuel supply such that the oxygen level within the beater mill is below a maximum mill oxygen threshold, and at least one of:
the temperature of the gas stream at the entrance of the beater mill is within a target mill entrance gas temperature range; and
the temperature of the gas stream at the exit of the beater mill is within a target mill exit gas temperature range.

12. The method of claim 11 , wherein the system further comprises:
obtaining the oxygen level within the beater mill from an oxygen sensor disposed in the beater mill or in the pulverized fuel conduit downstream of the beater mill.

13. The method of claim 12 , wherein the method further comprises:
calculating, with the controller, the oxygen level within the beater mill based at least in part on an oxygen level obtained by an oxygen sensor disposed in the furnace or in an outlet of the furnace.

14. The method of claim 12 , wherein the method further comprises:
supplying fuel to the beater mill from a fuel source, and
introducing, with the controller that is further in electronic communication with the fuel source, the fuel into the beater mill from the fuel source when the oxygen level within the beater mill is below the maximum mill oxygen threshold, and
at least one of:
the temperature of the gas stream at the entrance of the beater mill is within the target mill entrance gas temperature range; and
the temperature of the gas stream at the exit of the beater mill is within the target mill exit gas temperature range.

15. The method of claim 10 , wherein the fuel is coal.

16. A method for preheating a beater mill comprising:
rotating a beater wheel disposed within the beater mill to facilitate circulation of a gas stream between the beater mill and a furnace fluidly connected to the beater mill via a pulverized fuel conduit and a flue gas recirculation conduit;
generating a burner gas at stoichiometric conditions via a burner disposed within the flue gas recirculation conduit such that the burner gas joins and heats the gas stream circulating through the beater mill and the furnace;
adjusting at least one of an air supply and a fuel supply to the burner via a controller such that the temperature of the gas stream at a entrance of the beater mill is within a target mill entrance gas temperature range;
when the temperature of the gas stream at the entrance of the beater mill is within the target mill entrance gas temperature range, further adjusting at least one of the air supply and the fuel supply to the burner via the controller such that the temperature of the gas stream at a exit of the beater mill is within a target mill exit gas temperature range;
when the temperature of the gas stream at the exit of the beater mill is within the target mill exit gas temperature range, reducing the air supply to the burner via the controller such that a oxygen level within the beater mill is below a maximum mill oxygen threshold; and
when the oxygen level within the beater mill is below the maximum mill oxygen threshold, introducing a fuel from a fuel source into the beater mill.

17. The method of claim 16 further comprising:
obtaining the oxygen level within the beater mill from an oxygen sensor disposed in the beater mill or in the pulverized fuel conduit downstream of the beater mill.

18. The method of claim 16 , wherein the method further comprises:
calculating the oxygen level within the beater mill via the controller based at least in part on an oxygen level obtained by an oxygen sensor disposed in the furnace or in an outlet of the furnace.

19. The method of c

Assignees

• General Electric Technology Gmbh

Inventors

• Ristic Dragisa
• Daniel Rajkumar
• Kluger Frank Michael

Classifications

• F23K2201/1006

  Mills adapted for use with furnaces · CPC title

• B02C13/00

  Disintegrating by mills having rotary beater elements {; Hammer mills} · CPC title

• B02C25/00

  Control arrangements specially adapted for crushing or disintegrating · CPC title

• B02C13/13

  with horizontal rotor shaft and combined with sifting devices, e.g. for making powdered fuel · CPC title

• B02C23/24

  Passing gas through crushing or disintegrating zone ({B02C15/001}, B02C23/38, B02C23/40 take precedence) · CPC title